(1) Field of the Invention
The present invention relates to a content management device to manage reproduction of a content after the content being moved.
(2) Description of the Related Art
In recent years, a Digital Video Recorder is popular for recording a received broadcasting signal for Standard-definition Television (SDTV, analog broadcasting) into Hard Disk Drive (HDD) and optical disks such as Digital Versatile Disc Random Access Memory (DVD-RAM) by digitalizing and further encoding and compressing. Furthermore a digital video recorder, which is able to record satellite/terrestrial broadcasting signals for High-definition Television (HDTV), has been introduced into the market.
The digital broadcasting signal is characterized in that the qualities of video/audio are not deteriorated even after repeated duplications, unlike the analog broadcasting signal. It is, therefore, very significant to establish a rule to prevent from copying illegally so as to protect the copyright of content. Regarding the digital broadcasting signal, a copy control information is multiplexed in the digital video/audio contents, and thus a rule called copy-once, that allows to record a broadcasting signal only once when the broadcasting signal is received, has been introduced. Hence the copyright of content is protected.
Once the digital video/audio content with copy-once is recorded into a recording medium such as HDD and DVD-RAM, the copy control information is shifted to non-duplicable control information at that time, and the duplication of the content is prohibited. Yet it is allowed to move the content from a recording medium which has the content (a first recording medium) to another recording medium (a second recording medium).
One example of a technique related to duplication is disclosed in Japanese Laid-Open Patent application No. 2002-358241, “Copy management method of content, recording/reproducing device and reproducing device”. According to the technique in this example, the same number of virtual contents as the number of rights for duplicable times is available for a user, and the virtual content is moved at the time of duplication, while the virtual content in the source is deleted. Moreover it is disclosed that the number of rights for duplicable times are increased in the destination and are decreased in the source by the number of performed moving for duplication so as to protect from illegal duplication.